tcp: relax listening_hash operations
softirq handlers use RCU protection to lookup listeners,
and write operations all happen from process context.
We do not need to block BH for dump operations.
Also SYN_RECV since request sockets are stored in the ehash table :
1) inet_diag_dump_icsk() no longer need to clear
cb->args[3] and cb->args[4] that were used as cursors while
iterating the old per listener hash table.
2) Also factorize a test : No need to scan listening_hash[]
if r->id.idiag_dport is not zero.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index bd5e8d1..83b3d0b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1893,7 +1893,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
if (!sk) {
get_head:
ilb = &tcp_hashinfo.listening_hash[st->bucket];
- spin_lock_bh(&ilb->lock);
+ spin_lock(&ilb->lock);
sk = sk_head(&ilb->head);
st->offset = 0;
goto get_sk;
@@ -1911,7 +1911,7 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
return sk;
icsk = inet_csk(sk);
}
- spin_unlock_bh(&ilb->lock);
+ spin_unlock(&ilb->lock);
st->offset = 0;
if (++st->bucket < INET_LHTABLE_SIZE)
goto get_head;
@@ -2119,7 +2119,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v)
switch (st->state) {
case TCP_SEQ_STATE_LISTENING:
if (v != SEQ_START_TOKEN)
- spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
+ spin_unlock(&tcp_hashinfo.listening_hash[st->bucket].lock);
break;
case TCP_SEQ_STATE_ESTABLISHED:
if (v)
